Zinc Reduces Severity and Duration of Colds

There is no dispute about the importance of zinc in our diets. It is an essential nutrient throughout our lives and even for foetal development. There has been dispute, though, about the efficacy of zinc supplements. Clinical studies in the past have yielded mixed results and at least one study argued that zinc showed no evidence of reducing the duration of the common cold. An updated review now shows that zinc can reduce the severity and duration of colds.

About the Study

A 1999 study by the Cochrane Systematic Review concluded that not only was there no strong evidence that zinc helped reduce the symptoms of colds, but that it had some undesirable side effects, including mouth irritation, diarrhoea and nausea. The updated review, published in the Cochrane Library, finds that there is ample evidence to suggest that zinc supplements in fact do significantly reduce both the severity and duration of colds.

Meenu Singh and Rashmi R. Das of the Postgraduate Institute of Medical Education and Research in Chandigarh, India, took data collected from 15 earlier trials with a total of 1360 participants and re-evaluated it. What they found was strong evidence that zinc supplements were of significant benefit to cold sufferers. Among other things, they concluded that:

If zinc is taken in tablet, syrup or lozenge form within a day of the onset of symptoms, it can reduce both the duration and severity of a cold.

Children who took zinc supplements regularly for 5 or more months had fewer colds and had to take less time off school.

A greater proportion of participants in the trials who took zinc cleared their symptoms at 7 days after the onset of colds compared to participants who took placebos.

Another thing the authors of this latest study noted was that those children who took zinc appeared to need to take less antibiotics than those who did not. This is important, because overuse of antibiotics leads to resistance to them and reduces their effectiveness when they are needed in severe illnesses.

What Does this Mean?

While this latest study adds strength to the argument that zinc may be an effective treatment for the common cold, Dr. Singh added the caution that more study was needed and that not enough was yet know about what the optimum formulation, dosage or duration of treatment may be. She also noted that the studies covered in her review only included healthy individuals and that further research needed to be undertaken on particular groups. She added that “it would be interesting to find out whether zinc supplementation could help asthmatics, whose asthma symptoms tend to get worse when they catch a cold."

Westerners who include meat and poultry in their diet usually get sufficient zinc from these foods, but vegetarians often get an insufficient amount of the mineral because the body does not readily absorb zinc from legumes and grains. Regular intake of zinc is important because it is not stored in the body. If you or your children suffer from colds, it may be worth taking zinc supplements as recommended by a health care professional.